Antimicrobial Properties of Natural Phenols and Related Compounds: Obtusastyrene and Dihydro-Obtusastyrene

Abstract

Factors influencing the antimicrobial properties of obtusastyrene and dihydro-obtusastyrene were studied. Both of these compounds were soluble in acetone, alcohol, and olive oil. In water, they were soluble at concentrations of 34 and 53 μg/ml, respectively. The minimal inhibitory concentrations against gram-positive bacteria and yeast were below 100 μg/ml. The compounds were not effective against gram-negative bacteria at 200 μg/ml or lower concentrations. With initial populations of cells greater than 10 ⁶ /ml, the concentrations of these compounds required to prevent growth were greater than with lower cell populations. Changing the p H of the growth medium did not decrease the effectiveness of these two compounds in the p H range of 3 through 8. Both obtusastyrene and dihydro-obtusastyrene were rapidly bactericidal to Staphylococcus aureus and Bacillus cereus at 25 μg/ml.